1. Field of the Invention
The present invention relates to a timepiece used while being carried like a wristwatch, a pocket watch or the like.
2. Description of the Related Art
Hitherto, generally in the wristwatch, in a case where there is performed a crown operation such as time setting, a crown is rotation-operated after it is pull-moved. Therefore, in the wristwatch, there is adopted a contrivance for making such that the crown is not moved carelessly in a direction along which the crown is pull-moved by an impact exerted on the wristwatch when it falls or the like.
As one example of this contrivance, there is known a crown structure of a thread lock type. In this crown structure, a male thread part is formed in an outer periphery of a case band outside pipe end part protruding from a case band outer face of a winding stem pipe attached to the case band, and a female thread part is formed in an inner periphery of a crown head that the crown attached to the winding stem pipe so as to be movable in an axial direction of the winding stem pipe has. And, the crown is locked by the fact that the female thread part is meshed with the male thread part by rotating the crown in its tightening direction, and a pull movement of the crown and a rotation operation after it are made possible by rotating the crown in its loosening direction reversely to the former, thereby releasing the above mesh (e.g., refer to JP-UM-A-7-26792 Gazette (paragraphs 0001-0012, FIG. 1-FIG. 2)).
Further, as other example of the above contrivance, there is known a timepiece in which a push movement member is disposed coaxially in regard to the crown, a stirrup shape member forming a loop around the crown and the push movement member is attached to a case band side, and one end of a lever is rotatably attached to the stirrup shape member by a pin. The lever is used in order to control a chronograph function by push-moving the push movement member. An intermediate part of this lever has a contact point for cooperating with the push movement member, and the other end of the lever is made an operation part having a concave face. In this timepiece, since the intermediate part of the lever contacts with the crown capable of being pull-moved on the occasion of the time setting, by this lever the crown can be suppressed from carelessly moving in a pull-moving direction (e.g., refer to JP-T-2004-502925 Gazette (claim, paragraphs 0001-0024, FIG. 1-FIG. 2) (the term “JP-T” as used herein means a published Japanese translation of a PCT patent application)).
In the timepiece described in the Patent Document 1, there is considered the fact that its user erroneously drops the timepiece under a state in which the crown is rotation-operated for the time setting or the like by releasing a lock by loosening the crown. In a case where the timepiece undergoes the impact in this manner, there is the fact that the crown is excessively moved in the direction along which it is pull-moved carelessly and there is considered a fear that, following upon it, the crown or the like is injured.
Further, in the timepiece described in the Patent Document 2, although a force retaining the lever to a stationary state such that the crown is not moved carelessly depends on a friction engagement force in a rotation slide part between the lever and the pin or a friction engagement force in a rotation slide part between the pin and the stirrup shape member, an abrasion in the rotation slide part gradually proceeds following upon a rotation operation of the lever. By it, in a case where there becomes a state in which the friction engagement force decreases by, e.g., a use for a long term or the like, it is difficult to recover the friction engagement force unless a repair is performed. And, if the timepiece undergoes the impact under such a condition, since the lever is rotated at once, it is impossible to impede the crown from being excessively moved following upon it in the direction along which it is pull-moved carelessly.